Apparatus and method for identifying a still image contained in moving image contents

ABSTRACT

Apparatus for identifying one or more still images in one or more moving image contents. An identifying unit is configured to identify one or more still images included in the moving image contents having one or more features that closely resemble particular features. A display controller is configured to cause the display on a timeline associated with the moving image contents of the location of an identified still image in at least one of the moving image contents.

TECHNICAL FIELD

The present invention relates to a content searching apparatus, acontent searching method, and a program. More particularly, theinvention relates to a content searching apparatus, a content searchingmethod, and a program for displaying the results of a search throughmoving image contents for images in a more comprehensible manner forverification by a user.

BACKGROUND ART

Some techniques for image search regarding image (moving image) contentsare proposed hereunder.

When the result of the search for images regarding an image content isto be displayed, it is customary to display an image of the first frameof the content obtained through the search as well as representativeimages of that content. Alternatively, if frames corresponding to asearch image are detected from the content as a result of the search,these frames may be displayed.

Also, there exist techniques which, given a list of search results,allow retrieved contents to be selectively reproduced for imageverification, such as described in, for example, Japanese Laid-OpenApplication 2003-289487.

Furthermore, in the process of editing a content, a timeline displayindicating the waveform of an audio signal of the content along thetemporal axis has been used in recent years to let the user betterrecognize the temporal length and reproduction position of the contentbeing edited.

DISCLOSURE OF THE INVENTION

However, if a plurality of results are typically obtained from thesearch, conventional techniques do not enable the search results to becompared with one another as moving images. As a result, it has beendifficult, if not impossible, to compare the retrieved contents in termsof what is contained inside based on the search results.

For example, according to the conventional techniques, thumbnails orrepresentative images are displayed as search results. The user has nochoice but to compare these thumbnails or representative images from aplurality of search results visually with one another, when comparingthe multiple contents represented thereby.

Also, according to the conventional techniques, each content includingthe images obtained as a result of the search can be reproduced forverification. However, it has been difficult, if not impossible, tosimultaneously reproduce multiple search results for comparison.

SUMMARY OF INVENTION

The present invention has been made in view of the above circumstancesand provides arrangements for displaying the results of a search throughmoving image contents in a more comprehensible manner for verificationby the user.

In accordance with one embodiment, apparatus is provided for identifyingone or more still images in one or more moving image contents.

The apparatus includes an identifying unit configured to identify one ormore still images included in the moving image contents that have atleast one feature that closely resembles one or more particularfeatures. A display controller is configured to cause the display on atimeline associated with the moving image contents of the location of anidentified still image in the moving image contents.

Preferably, the identifying unit identifies scenes in each of the movingimage contents that contain a still image whose features closelyresemble the particular features; and said identified scenes aredisplayed.

In one advantageous embodiment, different moving image contents aredisplayed concurrently.

In another embodiment, the display controller causes the display inalignment, on a common timeline axis, of the locations in the movingimage contents at which the identified still images are located.

In a further embodiment, the moving image contents include audioinformation associated with the moving image contents, and the displaycontroller causes the display of timelines of signal waveforms of theaudio information in respective scenes of the moving image contents.

In yet another embodiment the display controller causes the display ofindicia associated with respective ones of the moving image contents,the indicia representing durations of the scenes in respective movingimage contents.

Advantageously, the display controller causes the moving image contentsto be reproduced, and causes the display along the aforementionedtimeline of moving sliders representing the current reproductionpositions of the moving image contents.

As a feature, the identified still images in a plurality of the movingimage contents are concurrently displayed.

Advantageous Effects of Invention

Accordingly, it is possible to display the results of a search throughmoving image contents in a more comprehensible manner for verificationby the user.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a typical structure of a contentsearching apparatus as one embodiment of the present invention.

FIG. 2 is a schematic view showing a typical search image.

FIG. 3 is a schematic view of a typical display screen showing searchresults.

FIG. 4 is a schematic view of a typical screen showing contents beingreproduced on the screen of FIG. 3.

FIG. 5 is a schematic view of a typical screen showing the contentsbeing further produced over time since the state of FIG. 4.

FIG. 6 is a schematic view of a typical screen showing selected scenesbeing reproduced repeatedly.

FIG. 7 is a schematic view of a typical screen extracting and displayingonly the scenes including images similar to the search image.

FIG. 8 is a flowchart explanatory of a typical content input process.

FIG. 9 is a flowchart explanatory of a typical search result displayprocess.

FIG. 10 is a block diagram showing a typical structure of a personalcomputer.

DESCRIPTION OF EMBODIMENTS

Referring to the drawings, FIG. 1 is a block diagram showing a typicalstructure of a content searching apparatus in accordance with oneembodiment of the present invention.

This content searching apparatus 10 is an apparatus which has aplurality of moving image contents stored in a media archive 22 andwhich searches the stored contents for those including an input searchimage.

As shown in FIG. 1, the content search apparatus 10 is made up of acontent input section 21, the media archive 22, an image processingsection 23, a metadata database 24, and an image feature quantitydatabase 25. Also, the content searching apparatus 10 includes a searchimage input section 31, an image feature quantity extraction section 32,a search section 33, and a search result output section 34.

The content input section 21 receives the input of content data. Asdescribed above, the contents are moving image contents that may includesounds and captions as needed. For example, these contents may be thecontents edited as part of a TV program to be broadcast.

The media archive 22 stores the content data input from the contentinput section 21. For example, the media archive 22 stores large amountsof content data furnished with identification information foridentifying the individual contents and allows the data to be retrievedand output as needed.

The image processing section 23 analyzes the content data supplied fromthe content input section 21 and extracts metadata from the suppliedcontents. In this context, the metadata typically refers to informationabout scene change points of the contents, and information about pointsin time that are necessary for providing a timeline display to bediscussed later, as well as file names and data sizes. Also, themetadata may include such information as waveforms of audio signals inthe contents.

The metadata extracted by the image processing section 23 is used forcontents to be displayed on a timeline basis as will be discussed later.For example, the metadata extracted by the image processing section 23is stored in the metadata database 24 in correspondence with contentidentification information.

Also, the image processing section 23 analyzes the content data suppliedfrom the content input section 21, and extracts image feature quantitiesfrom the supplied contents. In this context, the image feature quantityis information used in a process performed by the search section 33, tobe discussed later, to obtain degrees of similarity to a search image.For example, where a single-frame still image making up part of acontent is divided into a plurality of predetermined areas, therepresentative color of each of these areas may be described usinginformation constituting the image feature quantity. As another example,the image feature quantity may be the information formed by a histogramof the pixel values of a single-frame still image. As a further example,the image feature quantity may be constituted by any other informationthat provides degrees of similarity to the search image in the processcarried out by the search section 33.

The image feature quantity extracted by the image processing section 23is stored into the image feature quantity database 25 typically incorrespondence with content identification information and a framenumber.

The search image input section 31 receives the input of a search imageas a still image. For example, the search image is any image selected bythe user. A search image is input whereby the media archive 22 issearched for those images of the stored contents that are similar to theinput search image.

As with the image processing section 23, the image feature quantityextraction section 32 extracts the one or more particular image featuresfrom the search image input through the search image input section 31.

The search section 33 compares the image feature quantity (i.e. theparticular image feature or features) extracted from the search image bythe image feature quantity extraction section 32, with the image featurequantities stored in the image feature quantity database 25 inaccordance with a predetermined principle. Through the comparison, thesearch section 33 calculates as a numerical value the degree ofsimilarity between the image feature quantity of the search image on theone hand, and the image feature quantity of each of the single-framestill images making up each of the contents stored in the image featurequantity database 25 on the other hand.

For example, the search section 33 determines the still images havingthe image feature quantities of which the degrees of similarity to theimage feature quantity of the search image are higher than apredetermined threshold value. The search section 33 then supplies thesearch result output section 34 with the identification information ofthe contents from which the still images have been detected, along withthe frame numbers of these images, thereby identifying the still imagesin the contents that closely resemble the search image. If, from asingle content, a plurality of still images have been detected whichpossess the image feature quantities whose degrees of similarity to theimage feature quantity of the search image are higher than apredetermined threshold value, then the search section 33 typicallysupplies the search result output section 34 with the frame number ofthe still image having the highest degree of similarity.

In the manner described above, the search section 33 determines thecontents from which the frames of the still images having high degreesof similarity to the search image (i.e., the frames of the still imagessimilar to the search image) are detected, and notifies the searchresult output section 34 of these contents.

Based on the identification information supplied from the search section33 regarding the contents, the search result output section 34 retrievesthe metadata of the contents from the metadata database 24. And thesearch result output section 34 includes a display controller togenerate display data for displaying the search result based on theframe numbers of the still images fed from the search section 33 and onthe retrieved metadata.

The display data to be output from the search result output section 34is sent typically to a display device, not shown, for display as imagesthat will be discussed later. In an alternative embodiment, the displaydevice may be included in the search result output section 34.

Explained next are examples of how the result of search is displayed bythe content searching apparatus 10.

FIG. 2 is a schematic view showing a typical search image (still image)that is input through the search image input section 31. This examplemakes up an image indicating a missile and its launching pad.

The search image may be arranged to be either displayed on the displaydevice or not displayed thereon.

FIG. 3 is a schematic view of a typical screen displayed on the displaydevice, not shown, based on the display data output from the searchresult output section 34. FIG. 3 indicates an example of the screendisplayed when, with the search image of FIG. 2 input through the searchimage input section 31, a search has been performed through the contentsstored in the media archive 22.

The screen shown in FIG. 3 has a search result display region 51. Thisexample shows the search result display region 51 indicating sevencontents from which the still images with high degrees of similarity tothe search image of FIG. 2 have been detected. And the search resultdisplay region 51 has regions 51-1 through 51-7 each displayinginformation about each of the above-mentioned seven contents.

The region 51-1 displays the information about the first content.

A still image display region 52-1 is a region that displays the stillimage which was detected from the first content and which has a highdegree of similarity to the search image. A notation “4113889.asf” shownat the top of the still image in the still image display region 52-1 isthe identification information identifying the first content.

A timeline display region 53-1 is a region that provides a timelinedisplay regarding the first content. In the illustration, the horizontaldirection corresponds to the temporal axis of the content.

In this context, the timeline display regarding a content is providedwhen a given content is displayed in such a manner that the user canvisually recognize the temporal length of the content as well as thetemporal location of the scenes and frames inside the content. Andalthough the timeline display regarding the content involves displayingthe content in question in one way or another, it does not mean that thecontent will be reproduced and displayed as a moving image. For example,the timeline display of a given content signifies that graphics,waveforms, symbols, etc., representing the content or its components aredisplayed along the temporal axis.

An inverted triangle symbol 61-1 displayed in the timeline displayregion 53-1 indicates the temporal location of that still image frame inthe first content which is displayed in the still image display region52-1.

A waveform display region 62-1 shown in the timeline display region 53-1is a region that displays the signal waveform of the sounds included inthe first content. Alternatively, the waveform display region 62-1 maydisplay the waveform of the image. As another alternative, the timelinedisplay region 53-1 may be arranged not to include the waveform displayregion 62-1.

A scene display region 63-1 shown in the timeline display region 53-1 isa region that displays representations of scenes in the first content.The scene display region 63-1 displays representations of each of thescenes in the first content in the form of a rectangle whose width(i.e., length) corresponds to the temporal length of the scene inquestion. That is, the scene display region 63-1 is seen displayingthree rectangles, which means the first content is made up of threescenes. The start point and end point of each scene are determined onthe basis of scene change point information included in the metadataretrieved from the metadata database 24. The start point and end pointof each scene are then used to display the rectangle corresponding tothe scene in question in the scene display region 63-1.

Each rectangle in the scene display region 63-1 is displayed in thecolor representative of the corresponding scene. The representativecolor of a given scene may be typically determined as the colorcorresponding to the largest number of pixel values from among the pixelvalues making up all frames within the scene in question. Alternatively,the representative color of each scene may be determined in some otherappropriate manner. In short, any color suitable for the scene ofinterest may be selected as the representative color of that scene.

For example, the representative color of a given scene may be determinedby analyzing the data of the corresponding content when display data isgenerated. As another example, the representative color of each scenemay be determined beforehand and included in the relevant metadata.

Likewise, a region 51-2 displays information about the second content.That is, a still image display region 52-2 displays the still imagewhich was detected from the second content and which has a high degreeof similarity to the search image. A timeline display region 53-2 is aregion that provides a timeline display of the second content.

Further, regions 51-3 through 51-7 display information about the thirdthrough the seventh contents, respectively, in the same manner as theregions 51-1 and 51-2.

In the ensuing description, the individual still image display regionsmay be referred to generically as the still image display region 52; theindividual timeline display regions may likewise be referred togenerically as the timeline display region 53; and the individualsymbols may also be referred to generically as the symbol 61, as long asthere is no need to distinguish between the individual regions orsymbols.

As shown in FIG. 3, the timeline display regions 53-1 through 53-7 havethe same length in the horizontal direction. And in the timeline displayregions 53-1 through 53-7, the symbols 61-1 through 61-7 have the samelocation in the horizontal direction of FIG. 3. That is, these symbolsare in alignment on a common axis of the timeline display regions,thereby depicting the location in the scenes of the respective contentsof the still image frames that closely resemble the search image.

That is, the search result output section 34 determines the displaypositions of the individual display regions as follows.

Of the first through the seventh contents, the content having thelongest temporal length from its start time up to the symbol 61 has itsstarting location aligned with the leftmost position of the timelinedisplay region 53. In FIG. 3, the fourth content has its startinglocation aligned with the leftmost position of the timeline displayregion 53. Also, of the first through the seventh contents, the contenthaving the longest temporal length from its end time up to the symbol 61has its ending location aligned with the rightmost position of thetimeline display region 53. In FIG. 3, the fourth and the fifth contentshave their ending locations aligned with the rightmost position of thetimeline display region 53.

Since the search section 33 has already determined the frame numbers ofthe still images having the high degrees of similarity to the searchimage as discussed above, it is possible to determine the temporallength from either the start time or the end time of a given content tothe symbol 61.

And based on the temporal lengths of the fourth and the fifth contents,the time corresponding to the unit length of the timeline display region53 in the horizontal direction is determined.

For example, the search result output section 34 defines the location inthe horizontal direction of the symbol 61 displayed in FIG. 3 as thecenter of the timeline display region 53. This in turn determines thelocations of the waveform display region 62 and scene display region 63displayed in the regions 51-1 through 51-7. And the search result outputsection 34 generates display data for displaying the image such as oneshown in FIG. 3.

In this example, the waveform displayed in the waveform display region62 of the timeline display region 53 is shown displayed in keeping withthe temporal axis. Alternatively, the timeline display of the contentsmay be provided in some other suitable manner. For example, the timelinedisplay region 53 may be arranged to exclude the waveform display region62 as discussed above. In short, the contents need only be displayed insuch a manner that the user can easily recognize their temporal axes.

And a button 71 shown in FIG. 3 is typically used as a search startbutton that constitutes a GUI part. For example, following the input ofthe search image shown in FIG. 2, operating the button 71 executes asearch for the still images having high degrees of similarity to theinput search image. That is, the screen of FIG. 3 is a screen displayedafter the user has operated the button 71.

A button 72 shown in FIG. 3 typically constitutes a GUI part and is usedto issue a command to reproduce the contents in the regions 51-1 through51-7 in FIG. 3. Likewise, a button 73 in FIG. 3 is typically used as abutton to stop the reproduction of the contents that was started byoperation of the button 72.

If the button 72 is operated in the state of FIG. 3, the contents in theregions 51-1 through 51-7 start to be reproduced, which causes thescreen shown in FIG. 4 to be displayed.

With the reproduction of the contents started on the screen of FIG. 4, amoving slider 64 indicating the reproducing position appears in thetimeline display region 53. The slider 64 is typically displayed as arectangular frame in red. As time elapses, the slider moves, and itslength increases in the horizontal direction of FIG. 4. The rightmostposition of the slider 64 represents the current reproducing location ofthe content.

In the example of FIG. 4, only a short time has passed since the startof the content reproduction, so that the moving image of the fourthcontent alone is being reproduced. That is, a slider 64-4 is displayedsuperposed on the waveform appearing in the waveform display region62-4. The rightmost position of the slider 64-4 is located approximatelyat the center of the leftmost rectangle displayed in the scene displayregion 63-4. Meanwhile, the rightmost positions of the sliders 64-1through 64-3 and 64-5 through 64-7 have yet to reach the leftmostrectangles displayed in the scene display regions 63-1 through 63-3 and63-5 through 63-7, respectively. That is, reproduction of the firstthrough third and fifth through seventh contents associated with displayregions 51-1 through 51-3 and 51-5 through 51-7 have not yet begun.

Thus in the example of FIG. 4, the moving image of only the fourthcontent is currently reproduced; the image being reproduced is displayedin a reproduced image display region 54-4. That is, the reproduced imagedisplay region 54-4 displays the moving image obtained by reproducingthe fourth content.

Since the content has already started to be reproduced in the example ofFIG. 4, the button 72 serves as a “pause” button that temporarily stopsthe content reproduction when operated.

As more time elapses from the state of the screen displayed as shown inFIG. 4, the screen indicated in FIG. 5 appears.

In the example of FIG. 5, with more time having elapsed since the startof the content reproduction, the slider 64 is shown longer in thehorizontal direction than in FIG. 4. Concomitantly with this, the secondand the third contents in the example of FIG. 5 now are reproduced inaddition to the fourth content.

That is, the sliders 64-2 through 64-4 are shown superposed on thewaveforms displayed in the waveform display regions 62-2 through 62-4,respectively. And the rightmost positions of the sliders 64-2 through64-4 are each located on one of the rectangles displayed in the scenedisplay regions 63-2 through 63-4.

Thus in the example of FIG. 5, the moving images of the second throughthe fourth contents are reproduced. The reproduced images are displayedin the reproduced image display regions 54-2 through 54-4. That is, thereproduced image display regions 54-2 through 54-4 display the movingimages obtained by reproducing the second through the fourth contents,respectively.

As more time elapses since the state in which the screen of FIG. 4 wasdisplayed, the slider 64 is further moved in the horizontal direction ofFIG. 5. Then the fifth, the sixth, the first, and the seventh contentsstart to be reproduced one after another. Thus the reproduced imagedisplay regions 54-5, 54-6, 54-1, and 54-7 display the moving imagesobtained by reproducing the respective contents. That is, the differentmoving image contents are displayed concurrently.

And when the rightmost position of the slider 64 coincides with thesymbol 61 in the vertical direction of FIG. 5, the image shown in thestill image display region 52 is displayed in the reproduced imagedisplay region 54 because that image in each of the contents now isreproduced. This allows the user to check comparatively how the firstthrough the seventh contents have been edited and how their images withhigh degrees of similarity to the search image have been displayed. Thatis, the user can not only verify where the object images (i.e., imagessimilar to the search image) are located in the contents but alsocompare the images before and after each object image as moving images.

Also, on the screen displaying the results of the search performed bythe content searching apparatus 10, the user may select a rectangle inthe scene display region 63 of the timeline display region 53, whichcauses the scene corresponding to the selected rectangle to bereproduced repeatedly. As mentioned above, each of the rectangles in thescene display region 63 is displayed corresponding to the relevant sceneof the content in question.

For example, suppose that the user wants to reproduce repeatedly thescene including the image displayed in the still image display region52-2 regarding the second content. In this case, the user selects thefifth rectangle from left among the rectangles displayed in the scenedisplay region 63-2 of the timeline display region 53-2. On the basis ofthe position of the symbol 61-2 in the vertical direction of FIG. 5, itcan be seen that the image displayed in the still image display region52-2 is included in the fifth scene of the second content.

In that, the screen shown in FIG. 6 is displayed. In the example of FIG.6, the fifth rectangle 63-2 a from left is selected and highlightedamong the rectangles displayed in the scene display region 63-2 of thetimeline display region 53-2. This causes the reproduced image displayregion 54-2 to display repeatedly the moving image of the scenecorresponding to the rectangle 63-2 a from the start time to the endtime of the scene in question.

It is assumed here that each of the rectangles in the scene displayregion 63 is displayed as a GUI part and that the user typicallyoperates a pointing device or the like, not shown, to select any of therectangles in the scene display region 63.

In that case, not only the second content but also the first as well asthe third through the seventh contents are reproduced repeatedly. Thatis, the reproduced image display region 54 displays the moving images ofthose scenes in all contents which correspond to the rectangle 63-2 afrom the start time to the end time of each scene.

For example, in the case of the first content, a moving image from ahalfway point of the second scene to a halfway point of the third sceneis displayed repeatedly in the reproduced image display region 54-1.Also, in the case of the third content, a moving image from around thebeginning of the sixth scene through the entire seventh scene up to ahalfway point of the eighth scene is displayed repeatedly in thereproduced image display region 54-3.

As described, no matter which scene is selected from whichever content,all contents displayed in the search result display region 51 arereproduced. In the example of FIG. 6, the rightmost position of theslider 64 is located slightly to the right of the symbol 61. For thisreason, the image reproduced immediately after the image shown in thestill image display region 52 is displayed in the reproduced imagedisplay region 54. In this case, an image of a missile being launched isdisplayed in the reproduced image display section 54.

In the example of FIG. 6, the fifth rectangle from left is selected fromamong the rectangles displayed in the scene display region 63-2, so thatall contents are reproduced at the locations corresponding to the symbol61. Thus the images displayed in the still image display regions 52-1through 52-7 are included in the moving images reproduced repeatedly inthe reproduced image display regions 54-1 through 54-7, respectively.With this arrangement, the user can comparatively check the individualcontents as moving images by focusing on their target images.

Also, the content searching apparatus 10 can extract from the contentsonly the scenes that include images similar to the search image. Forexample, by operating an operation section, not shown, of the contentsearch apparatus 10, the user can issue a command to display a list ofscenes including images similar to the search image.

FIG. 7 is a schematic view of a typical screen displaying a list ofscenes including images similar to the search image. This is a typicalscreen that appears when, for example, the screen of FIG. 3 is displayedas a result of the search through the contents using the image in FIG. 2as the search image. That is, the search image and the search result inthe example of FIG. 7 are the same as those discussed above by referenceto FIG. 3.

In FIG. 7, vertically arrayed regions 101-1 through 101-7 display thosescenes in the first through the seventh contents which include imagessimilar to the target or search image. Here, the horizontal direction ofthe regions 101-1 through 101-7 corresponds to the temporal axes of thescenes. The individual scenes are displayed as rectangles 112-1 through112-7 of which the lengths reflect the temporal length of each of thescenes.

In FIG. 7, the regions 102-1 through 102-7 display still images detectedfrom the individual contents as the images having high degrees ofsimilarity to the search image. That is, the images displayed in theregions 102-1 through 102-7 are the same as those displayed in the stillimage display regions 52-1 through 52-7 in FIG. 3.

In FIG. 7, inverted triangle symbols 111-1 through 111-7 point tospecific locations in the scenes represented by the rectangles 112-1through 112-7. The locations thus indicated by the symbols include theimages displayed in the regions 102-1 through 102-7. As shown in FIG. 7,the rectangles 112-1 through 112-7 are each displayed in such a mannerthat the symbols 111-1 through 111-7 are at the same position in thevertical direction of the illustration.

For example, of the scenes displayed in the regions 101-1 through 101-7,the scene with the longest temporal length from its start time up to thesymbol 111 has its starting location aligned with the leftmost positionof the region 101. In this case, the starting locations of the secondand the third scenes from the top are aligned with the leftmost positionof the region 101. Also, of the scenes displayed in the regions 101-1through 101-7, the scene with the longest temporal length from its endtime up to the symbol 111 has its ending location aligned with therightmost position of the region 101. In this case, the ending locationof the sixth scene from the top is aligned with the rightmost positionof the region 101.

And the leftmost edge 112-2 a of the rectangle 112-2 corresponding tothe scene with the longest temporal length from its start time up to thesymbol 111 is displayed highlighted typically using a particular color(e.g., red). Likewise, the rightmost edge 112-6 b of the rectangle 112-6corresponding to the scene with the longest temporal length from its endtime up to the symbol 111 is displayed highlighted typically using aspecific color (e.g., blue).

When the display is given as described above, the user can easilycompare the temporal lengths of the entire scenes, the temporal lengthsof the scenes from the start time up to the point at which the targetimage is displayed (i.e., up to symbol 111), and the temporal lengths ofthe scenes from the point at which the target image is displayed untilthe end time.

Through the above comparisons, it is easy to detect appropriate scenestypically when a new content is to be edited using the content dataaccumulated in the media archive 22. Also, it is possible efficiently tomanage the media archive 22 by, say, deleting the scenes that are highlylikely to overlap with one another. Furthermore, even if a broadcasttimetable is changed at the last minute, it is easy to verify whichcontent is to be broadcast.

In the past, when the result of an image search through contents wasdisplayed, it was customary to display the image of the first frame or arepresentative image of each content obtained as a result of the search.Where the frames corresponding to the search image were detected fromthe contents, the images of these frames were displayed.

However, where a plurality of results were obtained from the search, itwas difficult, if not impossible, to compare these results in the formof moving images by use of the conventional techniques. Consequently, itwas impossible, or at least difficult, to compare the contents in termsof what was contained inside based on the results of the search. Forexample, when thumbnails or representative images were conventionallydisplayed as the results of the search, the user had no choice but tocompare the contents in terms of what was contained inside by visuallychecking these thumbnails or representative images stemming from themultiple search results. Also, although the conventional techniquespermitted reproduction of each content containing the images obtainedfrom the search for verification purposes, it was extremely difficult tosimultaneously compare a plurality of search results constituting themultiple contents displayed as moving images.

According to the present invention, by contrast, the results of thesearch for images through moving image contents can be verifiedsimultaneously as a plurality of moving image contents as describedabove by reference to FIGS. 3 through 7. Consequently, the results ofthe search through moving image contents are displayed in a morecomprehensible manner for verification by the user.

Explained next by reference to the flowchart of FIG. 8 is a typicalcontent input process performed by the content searching apparatus 10 inFIG. 1.

In step S21, the content input section 21 receives the input of contentdata. As described above, the input contents are moving image contentsthat may include sounds and captions as needed. For example, thesecontents are the contents edited as part of a TV program to bebroadcast.

In step S22, the image processing section 23 analyzes the content datasupplied from the content input section 21 in step S21.

In step S23, the image processing section 23 extracts metadata based onthe result of the analysis in step S22. In this context, the metadatatypically refers to information about scene change points of thecontents, and information about points in time that are necessary forproviding a timeline display to be discussed later, as well as filenames and data sizes.

In step S24, the metadata database 24 stores the metadata extracted instep S23. The metadata is stored typically in correspondence withcontent identification information.

In step S25, the image processing section 23 extracts image featurequantities (e.g. particular features) based on the analysis in step S22.In this context, the image feature quantity is information used in theprocess performed by the search section 33 to obtain degrees ofsimilarity to a search image. For example, where a single-frame stillimage making up part of a content is divided into a plurality ofpredetermined areas, the representative color of each of these areas maybe described using information constituting the image feature quantity.As another example, the image feature quantity may be the informationformed by a histogram of the pixel values of a single-frame still image.

In step S26, the image feature quantity database 25 stores the imagefeature quantities extracted in step S25. The image feature quantitiesare typically stored in correspondence with content identificationinformation and frame numbers.

In step S27, the media archive 22 stores the data of the contents ofwhich the input was received in step S21. Typically, the media archive22 stores the content data together with identification information foridentifying the individual contents.

The contents are input and stored into the media archive 22 as describedabove.

Explained next by reference to the flowchart of FIG. 9 is a typicalsearch result display process performed by the content searchingapparatus 10 in FIG. 1.

In step S41, the search image input section 31 receives the input of asearch image that is a still image. The search image may be any imageselected by the user, and is input so as to search the contents storedin the media archive 22 for images similar to the search image inquestion.

In step S42, from the search image input through the search image inputsection 31 in step S41, the image feature quantity extraction section 32extract an image feature quantity in the same manner as in step S25.

In step S44, the search section 33 compares the image feature quantityextracted from the search image in step S43, with the image featurequantities stored in the image feature quantity database 25 inaccordance with a predetermined principle. Through the comparison, thesearch section 33 calculates as a numerical value the degree ofsimilarity between the image feature quantity of the search image on theone hand, and the image feature quantity of each of the single-framestill images making up each of the contents stored in the image featurequantity database 25 on the other hand.

In step S45, the search section 33 determines the still images havingthe image feature quantities of which the degrees of similarity to theimage feature quantity of the search image are typically higher than apredetermined threshold value, and determines identification informationabout the contents from which these still images were detected, as wellas the frame numbers of these still images. If, from a single content, aplurality of still images have been detected which possess the imagefeature quantities whose degrees of similarity to the image featurequantity of the search image are higher than a predetermined thresholdvalue, then the search section 33 determines the frame number of thestill image typically having the highest degree of similarity.

In the manner described above, the contents stored in the media archive22 are searched for those contents that include images similar to thesearch image of which the input was received in step S41.

In step S46, the search section 33 notifies the search result outputsection 34 of the results of the search in step S45. In this case, thesearch result output section 34 is typically supplied with theidentification information about the contents that include the stillimages similar to the search image and the frame numbers of these stillimages.

In step S47, the search result output section 34 generates display datafor displaying the search results based on the information supplied instep S46. For example, on the basis of the content identificationinformation, the search result output section 34 reads metadata aboutthe contents in question from the metadata database 24, and generatesdisplay data for displaying the search results based on the framenumbers of the still images and on the retrieved metadata.

The display data output from the search result output section 34 istypically sent to a display device for display as images to be describedlater. As a result of this, the screen such as the one discussed aboveby reference to FIG. 3 is displayed on the display device.

Later, in response to GUI operations on the display screen or the like,the search result output section 34 generates suitable display data fordisplaying the screens such as those shown in FIGS. 4 through 7.

In the manner described above, the search result display process iscarried out.

In the example discussed above by reference to FIG. 1, the contentsearch apparatus 10 was explained to include the content input section21 and image processing section 23. Alternatively, the content searchapparatus 10 may be arranged to exclude the content input section 21 andimage processing section 23. That is, the display data need only begenerated by searching the media archive 22, metadata database 24, andimage feature quantity database 25 each having data stored thereinbeforehand, for the contents including the images similar to the searchimage.

And in the foregoing description, the display screen for displaying theresults of search by the content searching apparatus 10 was shown toprovide the timeline display of the contents with their temporal axesset to correspond to the horizontal direction of the illustration.Alternatively, the contents may be shown on the timeline display in sucha manner that their temporal axes are arranged to correspond to thevertical direction of the illustration.

Incidentally, the series of the processes described above may beexecuted either by hardware or by software. Where the software-basedprocessing is to be carried out, the programs constituting the softwaremay be installed on a non-transitory computer-readable storage medium,such as a RAM or a non-volatile memory, over a network or from arecording medium into a computer incorporated in dedicated hardware.Such programs may be installed from the recording medium into thecomputer such as a general-purpose computer 700 shown in FIG. 10 or likeequipment capable of executing diverse functions based on the installedprograms.

In FIG. 10, a CPU (Central Processing Unit) 701 performs variousprocesses in accordance with programs stored in a ROM (Read Only Memory)702 or in keeping with programs loaded from a storage section 708 into aRAM (Random Access Memory) 703. Also, the RAM 703 may accommodate datanecessary for the CPU 701 to carry out the diverse processing.

The CPU 701, ROM 702, and RAM 703 are interconnected via a bus 704. Aninput/output interface 705 is also connected to the bus 704.

The input/output interface 705 is connected with an input section 706typically made up of a keyboard and a mouse, and with an output section700 typically composed of a display device such as an LCD (LiquidCrystal Display) and speakers. The input/output interface 705 is alsoconnected with a storage section 708 typically formed by a hard disk andwith a communication section 709 typically constituted by a modernand/or a network interface card such as a LAN card. The communicationsection 709 processes communications conducted over networks includingthe Internet.

A drive 710 is also connected to the input/output interface 705 asneeded. Removable media 711 such as a magnetic disk, an optical disk, amagneto-optical disk, or a semi-conductor memory may be attached to thedrive 710. Computer programs read from the removable media are installedas needed into the storage section 708.

Where the series of the above-described processes is to be carried outby software, the programs making up the software are installed onstorage media over networks including the Internet or from recordingmedia such as the removable media 711.

The recording media are offered to distribute the programs to users notonly as the removable media 711 apart from the apparatus proper shown inFIG. 10 and constituted by magnetic disks (including floppy disks(registered trademark)), optical disks (including CD-ROM (CompactDisk-Read Only Memory) and DVD (Digital Versatile Disk)),magneto-optical disks (including MD (Mini-Disk; registered trademark)),or semiconductor memories, each accommodating the programs; but also inthe form of the ROM 702 or the hard disk in the storage section 708,each accommodating the programs and incorporated beforehand in theusers' apparatus.

In this description, the series of the processes discussed above includenot only the processes carried out in the depicted sequence (i.e., on atime series basis) but also processes that may be conducted parallellyor individually and not necessarily chronologically.

It should be understood that the present invention when embodied is notlimited to the above-described embodiments and that variousmodifications. For example, various components of content searchingapparatus 10 in FIG. 1 may be embodied in one or more devices or serversthat may be connected to a network, such as the Internet. Somefunctions, described above, may be performed remotely from the site ofapparatus 10. Other variations and alternatives may be made of theinvention so far as they are within the scope of the appended claims orthe equivalents thereof.

The invention claimed is:
 1. Apparatus for displaying moving images ofdifferent moving image contents, the moving images containing one ormore still images having image features that match selected imagefeatures, said apparatus comprising: an identifying unit configured toidentify at least one particular still image included in differentmoving image contents, the identified still image having one or moreimage features that closely resemble one or more of the selected imagefeatures; and a display information generator configured to generateinformation to cause a display, on timelines associated with thedifferent moving image contents, of marker symbols representing thelocations of the identified still image in different ones of said movingimage contents, the marker symbols on the timelines associated with thedifferent moving image contents being displayed in alignment with eachother on a common axis of the timelines; the display informationgenerator being further configured to generate information to causeplural different moving images, as represented by the different movingimage contents, to be reproduced and displayed concurrently as pluraldifferent moving images of the different moving image contents.
 2. Theapparatus of claim 1, wherein said identifying unit compares said one ormore selected image features to corresponding features of still imagesin said different moving image contents.
 3. The apparatus of claim 1,wherein said identifying unit identifies scenes in each of saiddifferent moving image contents that contain a still image whosefeatures closely resemble said one or more selected features; andwherein said display information generator generates information tocause the display of said identified scenes.
 4. The apparatus of claim1, wherein said different moving image contents include audioinformation associated with said different moving image contents, andwherein said display information generator generates information tocause the display of timelines of signal waveforms of said audioinformation in respective ones of said different moving image contents.5. The apparatus of claim 3, wherein said display information generatorgenerates information to cause the display of indicia associated withrespective ones of said different moving image contents representingdurations and/or colors of the scenes in said respective moving imagecontents.
 6. The apparatus of claim of claim 1, wherein said displayinformation generator generates information to cause the display, alongsaid timelines, of moving sliders representing current reproductionpositions of the different moving image contents.
 7. The apparatus ofclaim 1, wherein said identifying unit identifies scenes in each of saiddifferent moving image contents that contain a still image whosefeatures closely resemble said one or more selected image features.
 8. Amethod for displaying moving images of different moving image contents,the moving images containing one or more still images having imagefeatures that match selected image features, said method comprising:identifying at least one particular still image included in differentmoving image contents, the identified still image having one or moreimage features that closely resemble one or more of the selected imagefeatures; causing a display on timelines associated with the differentmoving image contents of marker symbols representing the locations ofthe identified still image in different ones of said moving imagecontents, the marker symbols on the timelines associated with thedifferent moving image contents being displayed in alignment on a commonaxis of the timelines; and causing plural different moving images, asrepresented by the different moving image contents, to be reproduced anddisplayed concurrently as plural different moving images of thedifferent moving image contents.
 9. The method of claim 8, wherein saidone or more still images are identified by comparing said one or moreselected features to corresponding features of still images in saiddifferent moving image contents.
 10. The method of claim 8, whereinscenes in each of said different moving image contents that contain astill image whose features closely resemble said one or more selectedfeatures are identified; and wherein said identified scenes aredisplayed.
 11. The method of claim 8, wherein said different movingimage contents include audio information associated with said differentmoving image contents, and further comprising displaying timelines ofsignal waveforms of said audio information in respective ones of saiddifferent moving image contents.
 12. The method of claim 10, furtherdisplaying indicia associated with respective ones of said differentmoving image contents representing durations and/or colors of the scenesin said respective moving image contents.
 13. The method of claim ofclaim 8, further comprising displaying moving sliders along saidtimelines, said moving sliders representing current reproductionpositions of the different moving image contents.
 14. A non-transitorycomputer-readable medium encoded with instructions that, when read by acomputer, executes the method for displaying moving images of differentmoving image contents, the moving images containing one or more stillimages having image features that match selected image features,comprising: identifying at least one particular still image included indifferent moving image contents, the identified still image having oneor more image features that closely resemble one or more of the selectedimage features; causing a display on timelines associated with thedifferent moving image contents of marker symbols representing thelocations of the identified still image in different ones of said movingimage contents, the marker symbols on the timelines associated with thedifferent moving image contents being displayed in alignment on a commonaxis of the timelines; and causing plural different moving images, asrepresented by the different moving image contents, to be reproduced anddisplayed concurrently as plural different moving images of thedifferent moving image contents.
 15. Apparatus for identifying one ormore still images in plural different image contents representingdifferent moving images, said apparatus comprising: an image input unitconfigured to receive an input search image; an identifying unitconfigured to identify at least one still image included in said pluraldifferent moving image contents that match the inputted search image bycomparing the inputted search image to the still images in the pluraldifferent moving image contents; and a display information generatorconfigured to generate information to cause a display, on timelinesassociated with the different moving images, of marker symbolsrepresenting the locations in the plural different moving image contentsof a still image that matches the inputted search image, the markersymbols representing the locations of the still image in respective onesof the plural different moving image contents that matches the inputtedsearch image being displayed on the timelines associated with the pluraldifferent moving image contents and in alignment on a common axis of thetimelines.